Northern tree shrew

Viewing Hints

Tree shrews blend in with their surroundings and they are often found in the upper branches of their exhibit, so look sharp and look up!

Where to find me in the Zoo

Small Mammal House

Fun Facts

A tree shrew mom spends less than 25 minutes total with her young during the first 4 weeks of their lives.

Researchers found that the Pen-tailed Tree shrew in Malaysia was able to consume large amounts of naturally fermented nectar of up to 3.8% alcohol content the entire year without having any effects on behavior. Investigation to how these animals cope with that diet is still ongoing.

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Resembling long nosed squirrels, they are physically similar to some of the earliest mammals (think “Scrat” from the movie Ice Age). They are mainly brown in color with large, dark, lashless eyes; short, bare ears; and a large, wet nose. Their whiskers are short and inconspicuous and they have a long bushy tail that flicks upwards. Their feet have naked pads and sharp nails that help them when they climb.

Longevity

In the wild tree shrews typically live for 2-3 years. In captivity, the longest lived individuals have reached 12 years of age.

Behavior

Alert, diurnal and almost constantly active, tree shrews live life on the edge. They are constantly searching for food because their short, simple digestive tracts and rapid passage times require them to refuel frequently. Their constant motion and varying paths through the forest also helps them to avoid predators. They are wary, and few things escape their sharp eyesight, acute hearing and strong sense of smell. They are one of a handful of small mammals in which all of their senses are highly developed. Although they are known as tree shrews, they are not truly arborial and spend a great deal of time on the ground.

Reproduction

Tree shrews have an unusual system of maternal care that is very rare among mammals. Newborn tree shrews are altricial – which means that they are pink and hairless with closed eyes and ears. The mother, however, does not care for them in any way that is typical for most mammals. She does not groom them, clean the nest, or retrieve them if they are in distress. Instead, she gives birth in a nest that she herself never shares with them. They are left alone except for a few minutes every other day when the mother returns to the nest to nurse them. She enters and the babies feed frantically – taking in almost a third of their body weight in 60 seconds. After a minute or two the milk is gone and the babies are bloated, and without as much as a look back the mother leaves the nest, not to return for another two days. The mother tree shrew spends about 90 seconds with her babies every two days – a grand total of 25 minutes of maternal care until they are weaned in 4 weeks! Once the young leave the nest however, the mother tree shrew often devotes a great deal of time to their care and may continue to nurse them, provide them with solid food, and teach them to forage. This is the opposite of most mammals who provide a great deal of care while their young are helpless in the nest but abandon them when they leave. This unusual maternal care system requires many adaptations, and may function to protect the young from predators that might follow the mother to the nest.

Size

Body and head: 5 – 9". The tail is about the same length.

Weight

There are several species of tree shrew that range in weight from 3.5 to 10oz.

Diet

Tree shrews are omnivores. In the wild these animals primarily consume insects, fruit and a small amount of other vegetation. At the Zoo, the base diet for the animals consists of a combination of two complete feeds, fruits and vegetables. The enrichment portion of the diet consists of insects. The keepers will often hide the insects in a head of escarole, the animals will spend a great deal of time going through the leaves to locate their prey.

Geographic Range

Southeast Asia – from India and southwestern China through Malaysia, Borneo and the Philippines.

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